Traditional heating apparatuses may be, for example, electric kettles, electric cookers, electric stewpots, electric irons, roasters, electric griddles, electric fryers, electric heaters, etc. Such traditional heating apparatuses are generally provided with conventional heating elements, such as resistance wires, and are provided with temperature safety devices to protect the heating elements. Such temperature safety devices are consisted of temperature sensor-switches and temperature fuses. However, those temperature safety devices are passive safety devices, and the temperature of the heating elements could only be transferred to the temperature sensor-switches after the temperature rises for a period of time due to malfunction of the heating elements or incorrect operation of users, and then the temperature fuses could take actions accordingly. In this case, the high temperature may have already incurred certain damages to the heating elements of heating apparatuses.
Currently, several kinds of high efficient heating elements are available on the market, for example, semiconductor electric heating resistance films. If a heating apparatus is provided with such kind of semiconductor electric heating resistance films but still provided with the above-mentioned passive temperature safety devices, the malfunction of the heating elements or incorrect operation of users would incur even worse damages to the heating apparatus. Since the high efficient heating elements have a higher heating efficiency than conventional heating elements, the temperature of such high efficient heating elements could rise rapidly due to the malfunction of the heating elements or incorrect operation of users. In this case, it is not possible for the temperature sensor-switches to transfer the temperature of the heating elements to the temperature fuses in time. Thereby, before the temperature fuses could take any actions, the heating elements or even the whole heating apparatus may have already be destroyed. Thus, the temperature fuses could not act as temperature safety elements at all.
In addition, when traditional heating apparatuses with conventional heating elements heat objects to be heated, the temperature of heating elements and the temperature of the objects would not be detected at the same time and the relative relationship between those temperatures would not be considered. The heating apparatuses would continue heating the objects until the temperature of the objects reaches a pre-determined temperature. Sometimes, if the objects could not absorb all the energy generated from the heating apparatuses, the excess energy would be radiated and wasted. The problem would be even worse when heating apparatuses are provided with high efficient heating elements, since more energy would be generated from the high efficient heating element in a unit period of time, and more energy would not be absorbed by the objects to be heated.